Explanation: The standard period of 305 days has been chosen because this is approximately the normal lactation length of cows calving at intervals of 12 months. In tropical cattle, restricting the lactation records to 305 days would have less effect, as few cow’s milk for more than 305 days.

Explanation: Circumference of a chest (heart girth) has been found to be the measurement most closely correlated with weight. The Dairy Cattle Research Branch2 of the U.S.D.A. reported a table of heart girth weight equivalents from which a measuring tape was prepared. This tape has been used extensively for more than 20 years in connection with D.H.I.A. work and for the estimation of body weight in dairy cattle generally.

Explanation: RHA is Registered Holstein Ancestry. Each animal in the herd book has a calculated, recorded and reported percentage “Registered Holstein Ancestry” or “RHA.”

Explanation: A certain temperature has to be met before the milk can be transferred to a milk truck. The milk should have at least attained the temperature of 40 degrees F before being transferred to a milk truck.

Explanation: Direct Microscopic Clump Count (DMCC) for bacteria is not considered an official test for bacteria counts, it is used throughout the dairy industry to estimate bacteria colony forming units (i.e., “clumps”) in raw milk samples taken from the farm, the tank truck or the plant storage facility.

Explanation: A milking dairy cow drinks about 25 gallons of water each day. During periods of heat stress water intake may double.

Explanation: Whole milk, as defined by the Milk Act, which regulates milk content, contains at least 3.25 percent milk fat. It also contains at least 8.25 percent protein, sugar (or carbohydrates) and vitamins and minerals. Otherwise, whole milk is made up of water-about 87 percent.

Explanation: Calories are units of energy. Various definitions exist but fall into two broad categories. Gram calorie is defined as the approximate amount of energy needed to raise the temperature of one gram of water by one degree Celsius at a pressure of one atmosphere.

Explanation: all the ration ingredients provide energy. However, in the above mentioned option fat provides the highest concentration of energy.

Explanation: Energy results from the digestion of carbohydrates, protein, and fat. Net Energy Lactation (NEl) is the feed energy available for maintenance and milk production after digestive and metabolic losses.

Explanation: Total digestible nutrients (TDN) are another method of expressing the energy content of feeds or the energy requirements of cattle. TDN is comparable to digestible energy. It has been in use longer than the net energy system and more values are available for feedstuffs.

Explanation: The dry matter of plant and animal material would be its solids, i.e. all its constituents excluding water. The dry matter of food would include carbohydrates, fats, proteins, vitamins, minerals, and antioxidants. Carbohydrates constitute about 75% of dry matter of plants.

Explanation: Polysaccharides are the most abundant carbohydrates. A polysaccharide molecule can contain thousands of glucose units. These highly complex carbohydrates include starches, cellulose, and glycogen. Starch is the usual form in which carbohydrates are stored as energy by plants in the cell wall.

Explanation: Structural carbohydrates constitute of Cellulose, hemicellulose, and lignin.

Explanation: The relationship between cows and their gut microorganisms is mutualistic. This relationship can also be called symbiotic.